# sort 永久排序
fruits = ['apple',  'mango','orange', 'banana']
fruits.sort()
print(fruits)

fruits.sort(reverse=True)
print(fruits)

# sorted 临时排序
fruits = ['apple',  'mango','orange', 'banana']
print(sorted(fruits))

# reverse 反转列表
fruits = ['apple',  'mango','orange', 'banana']
fruits.reverse();
print(fruits);

# len 元素长度
fruits = ['apple',  'mango','orange', 'banana']
num=len(fruits);
print(num)